1. Field of the Invention
The present invention relates generally to a manufacturing apparatus of a head gimbal assembly (“HGA”), and more particularly to a bending apparatus of a terminal part of a long-tail suspension to be mounted onto a hard disc drive (“HDD”). Here, the HGA is a suspension assembly mounted with a magnetic head unit and a base plate, and also referred to as a head suspension assembly.
2. Description of the Related Art
The HDD typically includes a disc and a head stack assembly (“HSA”) configured to support and move a head to a desired position on a disc. The HSA has includes a carriage (also referred to an “actuator,” an “E block” having an E-shaped section, or an “actuator (“AC”) block”), and a HGA attached to a support member of the carriage (referred to as an “arm” hereinafter). The magnetic head unit includes a micro head core (simply referred to as a “head” hereinafter) configured to record and reproduce a signal, and a slider configured to support the head. The base plate is swaged with the arm.
The suspension serves as a flat spring to compress the slider toward the disc at a predetermined compression force. As the disc rotates, airflow (air bearing) occurs between the slider and the disc along with the rotation, and floats the slider above the disc surface. The floating slider is spaced from the disc by a predetermined distance due to a balance between the floating force and the compression force. In this state, the arm swings to move or seek the head to the desired position on the disc for information reading and writing.
A long-tail suspension is used to satisfy the recent high-speed transfer demand. The long-tail suspension extends an end of a suspension substrate that is electrically connected to the head and fixed onto the suspension, to a main flexible printed circuit (“FPC”) board that is fixed onto the carriage.
The suspension substrate extends from the magnetic head unit along the center of the suspension in the longitudinal direction of the suspension, and is then bent by 90° toward the outside of the suspension. Next, the suspension substrate is again bent at its end by 90° along the side surface of the suspension, and forms an aerial part that extends in air near the side surfaces of the suspension and the arm. A section of the suspension substrate from the aerial part to the main FPC is generally referred to as a long tail. The suspension substrate has a wiring pattern on a SUS substrate via an insulation layer. Thereafter, a terminal part deflected by 90° from the long tail is soldered with the main FPC.
Prior art include Japanese Patent Laid-Open Nos. S63-177599, H09-307048, and S60-189245.
An alignment between each terminal on the terminal parts of the suspension substrate and a corresponding one of terminals of the main FPC is necessary for a connection between the long tail and the main FPC. However, the alignment becomes difficult when a bending angle shifts from 90° in bending the terminal part, or when the bent position shifts from the boundary between the long tail and the terminal part. The conventional terminal part requires totally four terminals, i.e., two recording terminals and two reproducing terminals for one head, whereas the recent terminal part requires two additional floatation-amount controlling terminals. In addition, the conventional size of the terminal part having these terminals is maintained due to the restrictions under the standard. Hence, both the suspension substrate and the main FPC need to install six terminals at the terminal part that has conventionally provided four terminals and both require a more precise alignment due to the decreases of inter-terminal pitches. Therefore, more precise bending of the terminal part becomes necessary.